In general, various electric connectors are widely used in various types of electrical equipment, devices, and so on for electrical connection of a signal transmission medium having a flat plate shape (hereinafter, referred to as a flat plate-shaped signal transmission medium) such as a flexible printed circuit (FPC) and a flexible flat cable (FFC). For example, in an electric connector that is mounted and used on a printed wiring substrate as in Patent Literature 1 below, the flat plate-shaped signal transmission medium including the FPC, the FFC, and so on is inserted from an opening for medium insertion disposed at the front end part of an insulating housing (insulator). The flat plate-shaped signal transmission medium is inserted to be pinched at the part between a lower beam and an upper beam constituting contact members. Subsequently, the contact members are elastically displaced by, for example, an actuator (connection operation means) being rotated by a worker's operating force, and the upper beam and the lower beam of the elastically displaced contact members are put into a state of being pressure-welded to both surfaces of the flat plate-shaped signal transmission medium (FPC, FFC, and so on). Clamping of the flat plate-shaped signal transmission medium is performed as a result.
In a state where the flat plate-shaped signal transmission medium (FPC, FFC, or the like) is clamped by the contact members of the electric connector as described above, the contact members are electrically connected with respect to a signal pattern disposed in the flat plate-shaped signal transmission medium. As a result, a state occurs where the flat plate-shaped signal transmission medium is electrically connected to the wiring substrate side through one end portion of the contact member solder-connected to a conductive path on the wiring substrate, and signal transmission is performed with the electric connector interposed.
Nowadays, contact members arranged in a multipolar shape tend to be disposed at a narrow pitch in electric connectors as a significant decrease in size and height is in progress. Once each contact member is reduced in size and thickness so that the narrow-pitch contact member disposition is realized in this regard, the conductor resistance of the contact members increases and the resultant heat generation may lead to a rise in electric connector temperature. Accordingly, in existing electric connectors, a configuration in which a plurality of contact members is energized with a single transmission signal is adopted sometimes as means for reducing the conductor resistance of the contact members. A rise in temperature during signal transmission can be suppressed with an energization structure that is based on a plurality of contact members as described above.
As a matter of course, however, the adoption of a configuration in which a plurality of contact members is used for the transmission of a single signal causes the number of the contact members to increase, and then a problem arises in the form of the lengthening or heightening of an electric connector as a whole.